This summer architect Toyo Ito and I did a cool-sounding exhibition titled Furin (see note*). In the first meeting, Ito told me about his stance towards architecture. “Architecture is an act like pounding a pile into a flowing river. I am, however, more interested in the vortex created behind the pile rather than the pile itself.” Inspired by this statement, we were drawn into an involved discussion about such topics as a flock of birds flying deftly avoiding electric poles, a large group of fireflies who illuminate in sync, and a fractal relationship established by a tree trunk and its branches. In common here are phenomena that seem complex at first glance but are actually born of very simple laws, such as a whole composed of individuals, and a relationship with one’s proximity. The concept for the exhibition Furin was born on the spot.

Several hundred glass furin (wind chimes) flicker faintly in the dark. Each furin that reminds one of a firefly glows faintly and makes a cooling sound when it senses a human presence nearby. Furin adjacent to each other create a mesh-like network and relay a message to its neighboring furin that “a person has approached.” Furin that received the message start to glow and further relay the message, “a person seems to have entered the vicinity.” Although each behavior is simple, viewing the furin from a slightly removed distance reveals the propagation of a complex and beautiful pattern woven by many lights and sounds. That was the concept.

The book I’m introducing here, Nexus: Small Worlds and the Groundbreaking Science of Networks, provided us with the foundation for this concept. Have you heard that if you track down the acquaintance of an acquaintance of an acquaintance, etc., you’ll end up covering the entire population of the world by the 6th tier? Today’s scientists call this phenomenon the “small world phenomenon,” and are seriously working on it as a research subject. In the first half of this book, the principle of this phenomenon is explained along with achievements and activities of the scientists who discovered it.

For example, even in human relationships there are degrees from intimate to distant acquaintances. It appears that what makes this world small is the effect of this distant acquaintance. Each group clustered through each close acquaintance bridges to another group via a distant acquaintance. As a result, the world instantly becomes small. The concept that weak connections are more important than strong connections is interesting, and the scientists adequately phrase this as “the strength of weak links.”

The author Mark Buchanan used to be an editor of the science magazine Nature. He explains the most advanced theories to the general readers in easy to understand language while citing familiar examples. Why not take a peek at the reverse side of “complexity?” (from AXIS vol.137）